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Mk 2 Mine
The Anti-Tank Mine General Service Mark II was a British anti-tank blast mine used during the Second World War. It consisted of a body about in diameter and . The mine has a central fuze well accessed from the bottom, with a main charge in a cavity around the well consisting of about of TNT. The mine is fitted with a thin brass cover, which acts as a pressure plate. The cover is suspended over the main body of the main by four leaf springs. A ''Sorbo'' ring (Sorbo rubber sponge) can be fitted between the cover and the mine body, which absorbs shock and blast and allows the mines to be planted as close as without causing sympathetic detonation (normally five feet is the minimum safe distance). Sufficient pressure on the cover of the mine causes the cover to press downward onto the pressure cap of the fuze. This downward pressure forces the assembly surrounding the striker down until the striker retaining balls are aligned with a cavity. The balls are pushed aside and the str ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anti-tank Mine
An anti-tank mine (abbreviated to "AT mine") is a type of land mine designed to damage or destroy vehicles including tanks and armored fighting vehicles. Compared to anti-personnel mines, anti-tank mines typically have a much larger explosive charge, and a fuze designed to be triggered by vehicles or, in some cases, remotely or by tampering with the mine. History First World War The first anti-tank mines were improvised during the First World War as a countermeasure against the first tanks introduced by the British towards the end of the war. Initially they were nothing more than a buried high-explosive shell or mortar bomb with its fuze upright. Later, purpose-built mines were developed, including the Flachmine 17, which was simply a wooden box packed with explosives and triggered either remotely or by a pressure fuze. By the end of the war, the Germans had developed row mining techniques, and mines accounted for 15% of U.S. tank casualties during the Battle of Saint-Mih ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Firing Pin
A firing pin or striker is a part of the firing mechanism of a firearm that impacts the primer in the base of a cartridge and causes it to fire. In firearms terminology, a striker is a particular type of firing pin where a compressed spring acts directly on the firing pin to provide the impact force rather than it being struck by a hammer. The terms may also be used for a component of equipment or a device which has a similar function. Such equipment or devices include: artillery, munitions and pyrotechnics. Firearms The typical firing pin is a thin, simple rod with a hardened, rounded tip that strikes and crushes the primer. The rounded end ensures the primer is indented rather than pierced (to contain propellant gasses). It sits within a hole through the breechblock and is struck by the hammer when the trigger is "pulled". A light firing-pin spring is often used to keep the firing pin rearward. It may be termed a ''firing-pin return spring'', since it returns it to t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kilonewton
The newton (symbol: N) is the unit of force in the International System of Units (SI). It is defined as 1 kg⋅m/s, the force which gives a mass of 1 kilogram an acceleration of 1 metre per second per second. It is named after Isaac Newton in recognition of his work on classical mechanics, specifically Newton's second law of motion. Definition A newton is defined as 1 kg⋅m/s (it is a derived unit which is defined in terms of the SI base units). One newton is therefore the force needed to accelerate one kilogram of mass at the rate of one metre per second squared in the direction of the applied force. The units "metre per second squared" can be understood as measuring a rate of change in velocity per unit of time, i.e. an increase in velocity by 1 metre per second every second. In 1946, Conférence Générale des Poids et Mesures (CGPM) Resolution 2 standardized the unit of force in the MKS system of units to be the amount needed to accelerate 1 kilogram of mass at the rate o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pound-force
The pound of force or pound-force (symbol: lbf, sometimes lbf,) is a unit of force used in some systems of measurement, including English Engineering units and the foot–pound–second system. Pound-force should not be confused with pound-mass (lb), often simply called ''pound'', which is a unit of mass, nor should these be confused with foot-pound (ft⋅lbf), a unit of energy, or pound-foot (lbf⋅ft), a unit of torque. Definitions The pound-force is equal to the gravitational force exerted on a mass of one avoirdupois pound on the surface of Earth. Since the 18th century, the unit has been used in low-precision measurements, for which small changes in Earth's gravity (which varies from equator to pole by up to half a percent) can safely be neglected. The 20th century, however, brought the need for a more precise definition, requiring a standardized value for acceleration due to gravity. Product of avoirdupois pound and standard gravity The pound-force is the product ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kilogram
The kilogram (also kilogramme) is the unit of mass in the International System of Units (SI), having the unit symbol kg. It is a widely used measure in science, engineering and commerce worldwide, and is often simply called a kilo colloquially. It means 'one thousand grams'. The kilogram is defined in terms of the second and the metre, both of which are based on fundamental physical constants. This allows a properly equipped metrology laboratory to calibrate a mass measurement instrument such as a Kibble balance as the primary standard to determine an exact kilogram mass. The kilogram was originally defined in 1795 as the mass of one litre of water. The current definition of a kilogram agrees with this original definition to within 30 parts per million. In 1799, the platinum ''Kilogramme des Archives'' replaced it as the standard of mass. In 1889, a cylinder of platinum-iridium, the International Prototype of the Kilogram (IPK), became the standard of the unit of mass for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pound (mass)
The pound or pound-mass is a unit of mass used in British imperial and United States customary systems of measurement. Various definitions have been used; the most common today is the international avoirdupois pound, which is legally defined as exactly , and which is divided into 16 avoirdupois ounces. The international standard symbol for the avoirdupois pound is lb; an alternative symbol is lbm (for most pound definitions), # ( chiefly in the U.S.), and or ″̶ (specifically for the apothecaries' pound). The unit is descended from the Roman (hence the abbreviation "lb"). The English word ''pound'' is cognate with, among others, German , Dutch , and Swedish . These units are historic and are no longer used (replaced by the metric system). Usage of the unqualified term ''pound'' reflects the historical conflation of mass and weight. This accounts for the modern distinguishing terms ''pound-mass'' and '' pound-force''. Etymology The word 'pound' and its cognates ultim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Second Battle Of El Alamein
The Second Battle of El Alamein (23 October – 11 November 1942) was a battle of the Second World War that took place near the Egyptian Railway station, railway halt of El Alamein. The First Battle of El Alamein and the Battle of Alam el Halfa had prevented the Axis powers, Axis from advancing further into Egypt. In August 1942, General (United Kingdom), General Claude Auchinleck had been relieved as Commander-in-Chief Middle East Command and his successor, Lieutenant-General William Gott was killed on his way to replace him as commander of the Eighth Army (United Kingdom), Eighth Army. Lieutenant-general (United Kingdom), Lieutenant-General Bernard Montgomery was appointed and led the Eighth Army offensive. The British victory was the beginning of the end of the Western Desert Campaign, eliminating the Axis threat to Egypt, the Suez Canal and the Middle Eastern and Persian oil fields. The battle revived the morale of the Allies, being the first big success against the Axis sin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mk 5 Mine
The Anti-Tank Mine, General Service, Mk V was a cylindrical, metal-cased United Kingdom anti-tank blast mine that entered service in 1943, during the Second World War. It was replaced in British service with the Mk 7 mine. Two versions of the mine were produced, the ''Mk. V'' and the ''Mk. VC'' with the same external dimensions. The only difference was that the Mk. VC had a half-sized explosive charge. The mine used a spider pressure plate that makes it resistant to blast overpressure. The spider rests on a central Mk 3 fuse (sometimes referred to as No.3 Mk I), which contains a spring-loaded striker held in place by a shear pin. The mine, being made largely of steel tended to rust making its activation unpredictable. It is found in Angola, Egypt, Jordan, Libya, Mozambique, Sudan, and Zimbabwe Zimbabwe (), officially the Republic of Zimbabwe, is a landlocked country located in Southeast Africa, between the Zambezi and Limpopo Rivers, bordered by South Africa to the south, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sympathetic Detonation
A sympathetic detonation (SD, or SYDET), also called flash over or secondary/secondaries (explosion), is a detonation, usually unintended, of an explosive charge by a nearby explosion. Definition A sympathetic detonation is caused by a shock wave, or impact of primary or secondary blast fragments. The initiating explosive is called the donor explosive, the initiated one is known as the receptor explosive. In case of a chain detonation, a receptor explosive can become a donor one. The shock sensitivity, also called gap sensitivity, which influences the susceptibility to sympathetic detonations, can be measured by gap tests. If detonators with primary explosives are used, the shock wave of the initiating blast may set off the detonator and the attached charge. However even relatively insensitive explosives can be set off if their shock sensitivity is sufficient. Depending on the location, the shock wave can be transported by air, ground, or water. The process is probabilistic, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Second World War
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposing military alliances: the Allies and the Axis powers. World War II was a total war that directly involved more than 100 million personnel from more than 30 countries. The major participants in the war threw their entire economic, industrial, and scientific capabilities behind the war effort, blurring the distinction between civilian and military resources. Aircraft played a major role in the conflict, enabling the strategic bombing of population centres and deploying the only two nuclear weapons ever used in war. World War II was by far the deadliest conflict in human history; it resulted in 70 to 85 million fatalities, mostly among civilians. Tens of millions died due to genocides (including the Holocaust), starvation, ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Detonation
Detonation () is a type of combustion involving a supersonic exothermic front accelerating through a medium that eventually drives a shock front propagating directly in front of it. Detonations propagate supersonically through shock waves with speeds in the range of 1 km/sec and differ from deflagrations which have subsonic flame speeds in the range of 1 m/sec. Detonations occur in both conventional solid and liquid explosives, as well as in reactive gases. The velocity of detonation in solid and liquid explosives is much higher than that in gaseous ones, which allows the wave system to be observed with greater detail (higher resolution). A very wide variety of fuels may occur as gases (e.g. hydrogen), droplet fogs, or dust suspensions. In addition to dioxygen, oxidants can include halogen compounds, ozone, hydrogen peroxide and oxides of nitrogen. Gaseous detonations are often associated with a mixture of fuel and oxidant in a composition somewhat below conventional flammabil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shock (mechanics)
A mechanical or physical shock is a sudden acceleration caused, for example, by impact, drop, kick, earthquake, or explosion. Shock is a transient physical excitation. Shock describes matter subject to extreme rates of force with respect to time. Shock is a vector that has units of an acceleration (rate of change of velocity). The unit ''g'' (or g) represents multiples of the acceleration of gravity and is conventionally used. A shock pulse can be characterised by its peak acceleration, the duration, and the shape of the shock pulse (half sine, triangular, trapezoidal, etc.). The shock response spectrum is a method for further evaluating a mechanical shock. Shock measurement Shock measurement is of interest in several fields such as *Propagation of heel shock through a runner's body *Measure the magnitude of a shock need to cause damage to an item: fragility. *Measure shock attenuation through athletic flooring *Measuring the effectiveness of a shock absorber *Measuring th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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